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L. Grassi et al.
two species of RNA (P<2 x 10-16, odds ratio: 2.31, 95% confidence interval: 2.08–2.57; Fisher exact test) (Figure 5D). Of the 2,122 gene-level comparisons with a posterior probability of differential expression >0.8, over 70% had a log fold change sign in the genes matching that identified in the corresponding circRNA. Although circRNA are typ- ically generated co-transcriptionally, the remainder may reflect cell type-specific competition in their biogenesis with canonical splicing of linear RNA.52 Several mecha- nisms of action have been discovered for ncRNA, but only a handful of circRNA have been experimentally verified as functional.41,43 Furthermore, their functions are distinct from those of their host genes, preventing functional infer- ences from the analysis of the GO terms of host genes.
Data visualization and download
We have developed a website (https://blueprint. haem.cam.ac.uk/bloodatlas/) for generating graphical repre- sentations of the data and downloading expression values. Its functionality is showcased in Online Supplementary Figure S5.
Discussion
We explored the coding and non-coding transcriptional landscapes of 90 samples comprising 27 different mature hematopoietic cell types (Figure 1A and B). Our aim was to determine how these cell types achieve their unique
A
B
Figure 5. Continued on the following page.
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